Brake.



C. B. MILLS.

BRAKE.

APPLICATION FILED MAR. 30, I914- ]Patented July 3, 1917.

W M a g muwE iv can snares Parser oration.

CHESTER B. MILLS, OF EAST. MGKEESPORT, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC AND MANUFACTURING UOMPAN Y, A CORPORATION OF PENNSYL- VANIA.

BRAKE.

. Specification of Letters Patent.

Patented July a, rat a.

Application filed March 30, 1914. Serial No. 828,202.

To all whom it may concern:

Be it known that I, CHESTER B. MILLS, a citizen'of the United .States, and a resident of East McKeesport, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Brakes, of which the following is a specification. v

My invention relatesto brakes forholsting apparatus and similar mechanisms, and it has particular reference to brakes that are controlled by electromagnetic devices.

My invention has for its object to provide asimple and convenient. means for adjustmg a brake to compensate for wear incident to its operation, and thus maintain proper conditions for efiicient operation. A

In the operation of electromagnetically controlled brakes, it is-necessary, at intervals, to adjust the means for connecting the movable member. of the actuatin magnet to the brake shoes in order to maintain the proper relation between the parts of the magnet. The normal position of themovable member of the magnet varies as thebrake shoes become thinner because of wear, and, consequently, the initial pull of the'magnet is decreased as the distance of the air gap between its relativelymovable parts is increased. l

I provide a, brake having an actuating lever that is composed of two relatively movable arms. The angle formed by the two arms is controlled by an adjustable threaded screw or bolt, thus providmg, in effect, an arrangement By means of such an arrangement, adjustments of any desired amount may be made with convenience, and precision and eflicient operating conditions may thereby be maintained.

The details of my invention are described in-connection with the accompanying drawings in which Figure 1 is an end view, in elevation, of a brake mechanism constructed in accordance with my invention and a wheel to which it is applied. Fig. 2 is a side View, in elevation of the mechanism of Fig. 1. Fig. 3 is a fragmentary view of a modification of my invention.

A brake wheel 1 is mounted on a shaft 2 of an electric motor (not shown) and-is an intermediate portion of similar to that of a micrometer.

provided with a suitable periphery 3 that is adapted for frictional engagement with cooperatin shoes. The brake comprises a brake member 4 that is adapted to be mounted upon any suitable support, and comprises an upright portion 5; Two curved levers 6 are pivotally supported upon pins 7 that are located near the central portion of the base member 4. The .arms 6 extend upwardly at the sides of the wheel 1, and are connected, at their upper ends, by links 8. Each of the levers 6 is provided with a brake shoe 9, the brake shoes being located at diametrically opposite sides of the wheel 1. The levers 6 are normally pressed toward each other by helical springs 10 the outer ends of which bear against fianged washers 11 that are mounted upon a, rod 12 and are restrained from axial electromagnet 13, that is mounted upon the upright portion 5, has a movable armature 14. A lever 15, comprises two arms 16 and 17 that connect the armature 14'to a pin 18 which forms a pivotal connection for the links 8. The arm 16 is rovided witha projecting portion 19 which the arm 17 by meansof a screw 20. The screw 20 is provided with oppositely threaded portions 21 and 22 that coact, respectively, with correspondingly threaded holes in the arm 17 and in the projecting portion 19. The angle formed by the arms 17 and 18 may be varied by properly adjusting the screw 20. R0- tation of the screw 20 is ing plate 23 and a locking screw 24.

It may be assumed that the various parts occupy their respective positions, as illustrated. The shoes 9 are pressed against the periphery 3 of the wheel 1 by the force of the springs 10 which act against the levers 6. In this position of the brake, no current is supplied to the windings of the electromagnet 13 and the armatureinember 14 is separated from the stationary portion of movement thereon. An

is connected toprevented by a lockrate thelevers 6 by means of the toggle joint formed by the links 8, whereupon the wheel 1 will be allowed to rotate freely. Upon the breaking of the circuit which supplies energy to the windings of the electromagnet 13, the armature 14 will be released, and the springs 10 Will again apply the brake shoes 9 to the periphery of'the wheel 1. As the brake shoes become worn, the'levers 6 are separated by a smaller distance when the shoes are in their respective operative positions, and the upper end of the lever 15 occupies a lower position than that normally occupied by it. The result is to increase the air gap between the armature 1,4 and the stationary portion of the electromagnet 13. Since the reluctance of the magnetic. circuit is thus increased, the pull of the magnet is decreased in the same proportion, and the efliciency of the brake is thereby impaired.

Y It is necessary, therefore, at intervals, to adjust the mechanism in order to maintain the proper distance between the armature '14 and thecoacting parts of the magnet 13.

This may be readily accomplished by means of the screw 20, it being necessary merely to turn it in the proper direction to separate the projecting portion 19 and the intermediate portion of thearm 17 1 Referring to Fig. 3, a modification of the adjusting device comprises ascrew 25 which is similar to the screw 20 in Fig. 1, except that the similarly threaded portions 26 and 27 are provided with threads of different pitch. The mechanism of Fig. 3 difiiers in no other material respect from the mechanism of Fig. 1.

It will be noted that I have provided a simple and effective means for adjusting the relative positions of the coacting parts of the actuating magnet.

I claim as my invention:

1. In a brake, the combination with a brake shoe, and an electromagnet comprising a movable portion, of means for operatively connecting said movable portion to said shoe, said meanscomprising 'a lever having two -relatively movable parts, and adjustable means for connecting said parts.

2. In a brake, the combination with a brake shoe, and an electromagnetic actuating device therefor, of means for connecting said device to said shoe, said means comprising an armature member, a pair of pivotally mounted arms and adjustable means for connecting said armsto vary the normal position of said armature member;

3. Ina brake, the combination with a brake shoe, and an electromagnetic device for actuating said shoe, of means for 0 eratively connecting said device to said s cc, said means comprising an armature member, a pair of relatively movable member and adjustable means for connecting sail members to regulate the initial air gap between said armature member and said device.

4:. In a brake, the combination with a brake shoe, and an electromagnet comprising a movable member, of means for connecting said movable member to said shoe, said means comprising a pair of oppositely extending arms having a pivotal support at adjacent ends, and adjustable means for locking said arms against relative movement.

V 5. In a brake, the combination with a brake shoe, and an electromagnet comprising a movable member, of means for operatively connecting said member to said shoe, said means comprising a lever having two pivotally mounted arms, and means for locking said arms against relative movement.

6. In a brake, the combination with a wheel, a brake shoe, and means for actuating said shoe to engage said wheel, of means comprising'an electromagnet having a movable member for releasing said shoe from engagement with said wheel, and means for adjusting the normal position of said movable member.

7. In a brake, the combination with a brake shoe, and a device for actuating said shoe, of means for operatively connecting said device to said shoe, said meansv comprising a pair of relatively movable members having a common pivotal support, and adjustable means for rigidly 1 connecting said members.

8. In a brake, the combination with a brake shoe, and a device for actuating said shoe, of means for operatively connecting said device to said shoe, said means comprlsing a pair of relatively movable members having a common pivotal support, and a single adjustable member for connecting said members.

9. In a brake, the combination with a brake shoe and an electromagnet for actuating said shoe, of means for operatively connecting said electromagnet to said shoe, said means comprising a pair of relatively,mov-

able members and an adjustable member having portions respectively. provided with,

screw-threads bearing different relations to the axis of. the adjustable member.

10. In a brake, the combination with a wheel, a brake shoe, and means for actuating said shoe to engage said wheel, of means comprising an electromagnet having a m0vable member for releasing saidshoe from engagement'with said wheel, and means for adjusting the normal position of said mov-.

able member, said adjusting means comprising a member having portions respectively provided with right-hand' and with lefthand screw threads.

11. In a brake, the combination with a brake shoe and an actuating device therefor, of means for 0 said device to said sho mg a pair of relatively movable members, and an adjustable member having portions provided with oppositely-extending screw threads.

4 'In testimony whereof, I have hereunto peratlvely connectlng subscribed my name this 25th day of Mar.

O. C. SQHOENFELD, B. B. HINEs. 

